Enhancement of Both Long-Term Depression Induction and Optokinetic Response Adaptation in Mice Lacking Delphilin

In the cerebellum, Delphilin is expressed selectively in Purkinje cells (PCs) and is localized exclusively at parallel fiber (PF) synapses, where it interacts with glutamate receptor (GluR) δ2 that is essential for long-term depression (LTD), motor learning and cerebellar wiring. Delphilin ablation exerted little effect on the synaptic localization of GluRδ2. There were no detectable abnormalities in cerebellar histology, PC cytology and PC synapse formation in contrast to GluRδ2 mutant mice. However, LTD induction was facilitated at PF-PC synapses in Delphilin mutant mice. Intracellular Ca2+ required for the induction of LTD appeared to be reduced in the mutant mice, while Ca2+ influx through voltage-gated Ca2+ channels and metabotropic GluR1-mediated slow synaptic response were similar between wild-type and mutant mice. We further showed that the gain-increase adaptation of the optokinetic response (OKR) was enhanced in the mutant mice. These findings are compatible with the idea that LTD induction at PF-PC synapses is a crucial rate-limiting step in OKR gain-increase adaptation, a simple form of motor learning. As exemplified in this study, enhancing synaptic plasticity at a specific synaptic site of a neural network is a useful approach to understanding the roles of multiple plasticity mechanisms at various cerebellar synapses in motor control and learning

‘Medusa head ataxia’: the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 3: Anti-Yo/CDR2, anti-Nb/AP3B2, PCA-2, anti-Tr/DNER, other antibodies, diagnostic pitfalls, summary and outlook

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as ‘Medusa head antibodies’ due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook

Multiphasic contrast-enhanced multidetector-row CT of liver: Contrast-enhancement theory and practical scan protocol with a combination of fixed injection duration and patients' body-weight-tailored dose of contrast material

The introduction of multidetector-row CT (MDCT) has provided the abdominal radiologists with dramatic changes for the imaging of the liver. At just present, establishment of new and optimal injection protocol in multiphasic contrast-enhanced MDCT of the liver has been yearned because the difficulty and the importance to optimize the scan timing for each phase imaging have obviously increased because of the extremely rapid scan speed with MDCT scanners. Among technical factors employed in an injection protocol for multiphasic contrast-enhanced MDCT of the liver, to make an injection duration of contrast material fixed is the most important for the precise estimation of the scan timing for each phase imaging. With the fixed injection duration, the peak enhancement time of the aorta, portal vein, and liver constantly appear approximately 10, 20, and 30 s after the any fixed injection durations (completion of injection of contrast material), respectively. Moreover, using a combination of the fixed injection duration and patients' body-weight-tailored dose of contrast material, similarity of time-density curves of each organ in shape and pattern can be achieved for individual patient with different body weight. In this issue, we will attempt to determine an ultimately optimal, but practical injection/scan protocol to successfully realize multiphasic contrast-enhanced MDCT of the liver based on the contrast-enhancement theory. (C) 2006 Elsevier Ireland Ltd. All rights reserved

Diffusion-weighted MR imaging in the evaluation of pancreatic exocrine function before and after secretin stimulation

OBJECTIVES: To evaluate diffusion weighted MR imaging before and after secretin stimulation in the assessment of pancreatic exocrine function in the setting of chronic pancreatitis

Effect of duration of contrast material injection on peak enhancement times and values of the aorta, main portal vein, and liver at dynamic MDCT with the dose of contrast medium tailored to patient weight

AIM: To investigate the effects of contrast material injection duration on peak enhancement times and attenuation values of the aorta, main portal vein, and liver at MDCT when the dose of contrast material is adjusted to patient weight

Laser oscillation in monolithic molecular single crystals

This is a preprint of an article published in ADVANCED MATERIALS,Vol 17,2073-2077(2005)ArticleAdvanced Materials. 17(17): 2073-2077 (2005)journal articl